1. Field of the Invention
The present invention relates generally to devices for opening sealed containers. More particularly the invention concerns a manually operated apparatus for removing screw-on lids from jars.
2. Description of the Prior Art
Jars and bottles, commonly made of glass and plastic have long been employed to contain and store various types of foods and materials. Typically, such containers are provided with screw-type closure lids, which attach to the jars by cooperating threads. In order to properly seal the container, the lid is generally tightly fitted to its associated jar often making it difficult to remove the lid from the container. Entrapment of small amounts of the contained material within the threads may also contribute to difficulty in loosening the jar lid as will corrosion of the lid with the passage of time. Even under the best of conditions, the very young, the elderly and persons with arthritis and like infirmities often find it extremely difficult to accomplish the task of removing the threaded lid from its associated container.
A wide variety of jar opening devices have been suggested in the past. For example, several container opening devices of the strap wrench type have previously been designed and marketed. Generally these devices include a friction buckle arrangement along with an elongated handle for removing the lid. In other prior art under the counter type devices a cam lock principle is used such as “V” notch and cam-lock for gripping the jar lid. These devices generally require the user to hold the container in position while turning it. When the container is made of glass, breakage of the container is possible, resulting in the possibility of severe lacerations to the hand of the user.
A more sophisticated type of container opening device is described in U.S. Pat. No. 5,430,923 issued to Parent et al. The Parent et al., device includes a mechanical drive for causing relative rotation to occur between the container cap and a cap-engaging unit. The mechanical drive brings the cap unit into engagement with the cap and then slips to permit the cap to be unscrewed from the container. A control unit senses the torque created by the relative rotation between the cap and the cap engaging unit and when a drop in torque is sensed, the control unit causes the drive to move the cap and the cap-engaging unit out of operable engagement.
U.S. Pat. No. 3,795,158 issued to Morita discloses a jar lid remover which comprises a jar base clamp that is adjustable into a clamping relationship with the base of the jar and a jar lid clamp that is adjustably positioned directly above the base clamp for vertical adjustment. The jar lid clamp is power driven in a manner such that the motorized application of lid unscrewing torque increases the extent of the clamping engagement of the clamp means on the lid so as to prevent torsional slipping during the jar lid unscrewing operation.